The proposed studies build upon an existing longitudinal study of respiratory health in relation to ambient air pollution. Approximately 3600 children from 12 communities in Southern California chosen to maximize contrast in exposure to ozone, particles, acids and nitrogen oxides are being followed over a 7-year period. The study is conducted at Univ of Southern California -- Dr. London was heavily involved in setting up the cohort while a faculty member there. Exposure assessment for the study comes from a combination of routine and supplementary stationary air monitoring, enhanced by timeactivity surveys from the children. Parents complete a detailed questionnaire at entrance into the study which includes history of the child's respiratory illnesses, allergies and current symptoms, residential history including housing characteristics known to influence indoor air quality, family data on smoking and respiratory illness, and the use of vitamin supplements. Outcomes under study include, change in pulmonary function measured yearly at the schools and acute illness as assessed by followup of all school absences by phone interview. To test the hypothesis that antioxdants protect against respiratory insult from oxidant air pollutants such as ozone and nitrogen oxides, we propose to noninvasively assess vitamin E stores using buccal cells collected. We are interested in modifying this published method for the collection of buccal cells for later vitamin E analysis to meet the requirements of the field data collection methods already in place. The process of collection of cells for vitamin E analysis would yield a pellet of cells which could be divided and part reserved for the extraction of DNA for future examination of genes that may be involved in susceptibility to respiratory effects of ozone. Respiratory outcomes of interest include growth in pulmonary function, as assessed by spirometry, and selfreported health conditions including asthma, chronic cough and episodes of acute respiratory illness as ascertained by school absence monitoring.